Several connection options are available with DPPI. Examples are given for how to create one-to-one and many-to-many connections.
One-to-one connection
This example shows how to create a one-to-one connection between the TIMER compare register and the SAADC start task.
The channel configuration is set up first. TIMER will publish its COMPARE0 event on channel 0, and SAADC will subscribe its START task to events on the same channel. When this is finished, the channel is enabled through the DPPIC.
NRF_TIMER20->PUBLISH_COMPARE[0] = (0 << TIMER_PUBLISH_COMPARE_CHIDX_Pos) | TIMER_PUBLISH_COMPARE_EN_Msk;
NRF_SAADC->SUBSCRIBE_START = (0 << SAADC_SUBSCRIBE_START_CHIDX_Pos) | SAADC_SUBSCRIBE_START_EN_Msk;
NRF_DPPIC20->CHENSET = DPPIC_CHENSET_CH0_Msk;
Many-to-many connection
The following example shows how to create a many-to-many connection, showcasing the DPPIC's channel group functionality.
A channel group that includes only channel 0 is set up first. Then the GPIOTE and
TIMER configure their IN0 and COMPARE0 events respectively to be published on
channel 0, while the SAADC configures its START task to subscribe to events on
channel 0. Through DPPIC, the CHG0 DISABLE task is configured to subscribe to events
on channel 0. After an event is received on channel 0 it will be disabled. Finally,
channel 0 is enabled using the DPPIC task to enable a channel group.
NRF_DPPIC20->CHG[0] = (DPPIC_CHG_CH0_Included << DPPIC_CHG_CH0_Pos);
NRF_GPIOTE20->PUBLISH_IN[0] = (0 << GPIOTE_PUBLISH_IN_CHIDX_Pos) | GPIOTE_PUBLISH_IN_EN_Msk;
NRF_TIMER20->PUBLISH_COMPARE[0] = (0 << TIMER_PUBLISH_COMPARE_CHIDX_Pos) | TIMER_PUBLISH_COMPARE_EN_Msk;
NRF_SAADC->SUBSCRIBE_START = (0 << SAADC_SUBSCRIBE_START_CHIDX_Pos) | SAADC_SUBSCRIBE_START_EN_Msk;
NRF_DPPIC20->SUBSCRIBE_CHG[0].DIS = DPPIC_CHENSET_CH0_Msk | DPPIC_SUBSCRIBE_CHG_DIS_EN_Msk;
NRF_DPPIC20->TASK_CHG[0].EN = 1;